Cu/SiO2 catalysts prepared by the ammonia evaporation method were applied to hydrogenation of diethyl malonate to 1,3‐propanediol. The calcination temperature played an important role in the structural evolution and ...Cu/SiO2 catalysts prepared by the ammonia evaporation method were applied to hydrogenation of diethyl malonate to 1,3‐propanediol. The calcination temperature played an important role in the structural evolution and catalytic performance of the Cu/SiO2 catalysts, which were systematically characterized by N2 adsorption‐desorption, inductively coupled plasma‐atomic emission spectros‐copy, N2O chemisorption, X‐ray diffraction, Fourier transform infrared spectroscopy, H2 tempera‐ture‐programmed reduction, transmission electron microscopy, and X‐ray photoelectron spectros‐copy. When the Cu/SiO2 catalyst was calcined at 723 K, 90.7%conversion of diethyl malonate and 32.3%selectivity of 1,3‐propanediol were achieved. Compared with Cu/SiO2 catalysts calcined at other temperatures, the enhanced catalytic performance of the Cu/SiO2 catalyst calcined at 723 K can be attributed to better dispersion of copper species, larger cupreous surface area and greater amount of copper phyllosilicate, which results in a higher ratio of Cu＋/Cu0. The synergetic effect of Cu0 and Cu＋is suggested to be responsible for the optimum activity.展开更多
Ionic liquids （ILs） based on 1,3-dialkylimidazolium and tetraalkylammonium cations were employed as a series of efficient, environmentally benign phase-transfer catalysts （PTCs） for the base-promoted monoalkylatio...Ionic liquids （ILs） based on 1,3-dialkylimidazolium and tetraalkylammonium cations were employed as a series of efficient, environmentally benign phase-transfer catalysts （PTCs） for the base-promoted monoalkylation of diethyl malonate. The influence of various heterogeneous bases on yields was studied. Good yields and high selectivity were obtained. Solvent-free, mild reaction condition, short reaction time, and easy purification were the merits of this method. The catalytic system （IL-hase） could also be recycled after the extraction of products with ether.展开更多
A green synthesis route of diethyl malonate by palladium catalyzed carbonylation of ethyl chloroacetate in the presence of phase transfer agent is carried out under mild conditions in good yield. The effects of reacti...A green synthesis route of diethyl malonate by palladium catalyzed carbonylation of ethyl chloroacetate in the presence of phase transfer agent is carried out under mild conditions in good yield. The effects of reaction temperature and different bases on the yield of diethyl malonate are also discussed.展开更多
Diethyl malonate being an initial raw material, processed with chlorination-replacement-desalination-vacuum rectification, is used to produce carbonyl diethyl malonate. An experiment for optimization determines that t...Diethyl malonate being an initial raw material, processed with chlorination-replacement-desalination-vacuum rectification, is used to produce carbonyl diethyl malonate. An experiment for optimization determines that the best reaction condition was： （1 reaction for 7 h at 10 ℃ with mole-ratio being 2.4 ＂ 1 between chloride and raw material （diethyl malonate）; （2 reaction for 4.5 h at 118 ℃ with mole-ratio being 1.2 ： 1 between the anhydrous sodium acetate and intermediate I. The final product carbonyl diethyl rnalonate recovery ratio reaches up to as high as 79.12% with a purity of 96.4%, which meets the market requirement. This synthesis technique has the advantages of simple process, moderate reaction conditions, high yield and low cost, being suitable for industrial scale production.展开更多
The title complex {CpEu CH(COOC 2H 5) 2 μ CH(COOC 2H 5) 2 } 2 crystallizes in the triclinic system, space group P1 with unit cell constants a=9.108(1), b=11.580(2), c=11.705(2) , α=70.42(1)...The title complex {CpEu CH(COOC 2H 5) 2 μ CH(COOC 2H 5) 2 } 2 crystallizes in the triclinic system, space group P1 with unit cell constants a=9.108(1), b=11.580(2), c=11.705(2) , α=70.42(1)°, β=73.83(1)°, γ=78.60(1)°, D c =1.602 g/cm 3 , M r=1070.76, V=1109.7(3) 3, Z=1, μ (Mo Kα )=28 66 cm 1 and F(000)=536, T=296K, R=0.028, R w =0.037. The geometry around the Eu ion can be described as a pentagonal bipyramid.展开更多
文摘Cu/SiO2 catalysts prepared by the ammonia evaporation method were applied to hydrogenation of diethyl malonate to 1,3‐propanediol. The calcination temperature played an important role in the structural evolution and catalytic performance of the Cu/SiO2 catalysts, which were systematically characterized by N2 adsorption‐desorption, inductively coupled plasma‐atomic emission spectros‐copy, N2O chemisorption, X‐ray diffraction, Fourier transform infrared spectroscopy, H2 tempera‐ture‐programmed reduction, transmission electron microscopy, and X‐ray photoelectron spectros‐copy. When the Cu/SiO2 catalyst was calcined at 723 K, 90.7%conversion of diethyl malonate and 32.3%selectivity of 1,3‐propanediol were achieved. Compared with Cu/SiO2 catalysts calcined at other temperatures, the enhanced catalytic performance of the Cu/SiO2 catalyst calcined at 723 K can be attributed to better dispersion of copper species, larger cupreous surface area and greater amount of copper phyllosilicate, which results in a higher ratio of Cu＋/Cu0. The synergetic effect of Cu0 and Cu＋is suggested to be responsible for the optimum activity.
文摘Ionic liquids （ILs） based on 1,3-dialkylimidazolium and tetraalkylammonium cations were employed as a series of efficient, environmentally benign phase-transfer catalysts （PTCs） for the base-promoted monoalkylation of diethyl malonate. The influence of various heterogeneous bases on yields was studied. Good yields and high selectivity were obtained. Solvent-free, mild reaction condition, short reaction time, and easy purification were the merits of this method. The catalytic system （IL-hase） could also be recycled after the extraction of products with ether.
文摘A green synthesis route of diethyl malonate by palladium catalyzed carbonylation of ethyl chloroacetate in the presence of phase transfer agent is carried out under mild conditions in good yield. The effects of reaction temperature and different bases on the yield of diethyl malonate are also discussed.
基金Supported by the Innovation Fund for Technology Based Firms(10C26224212340)
文摘Diethyl malonate being an initial raw material, processed with chlorination-replacement-desalination-vacuum rectification, is used to produce carbonyl diethyl malonate. An experiment for optimization determines that the best reaction condition was： （1 reaction for 7 h at 10 ℃ with mole-ratio being 2.4 ＂ 1 between chloride and raw material （diethyl malonate）; （2 reaction for 4.5 h at 118 ℃ with mole-ratio being 1.2 ： 1 between the anhydrous sodium acetate and intermediate I. The final product carbonyl diethyl rnalonate recovery ratio reaches up to as high as 79.12% with a purity of 96.4%, which meets the market requirement. This synthesis technique has the advantages of simple process, moderate reaction conditions, high yield and low cost, being suitable for industrial scale production.
文摘The title complex {CpEu CH(COOC 2H 5) 2 μ CH(COOC 2H 5) 2 } 2 crystallizes in the triclinic system, space group P1 with unit cell constants a=9.108(1), b=11.580(2), c=11.705(2) , α=70.42(1)°, β=73.83(1)°, γ=78.60(1)°, D c =1.602 g/cm 3 , M r=1070.76, V=1109.7(3) 3, Z=1, μ (Mo Kα )=28 66 cm 1 and F(000)=536, T=296K, R=0.028, R w =0.037. The geometry around the Eu ion can be described as a pentagonal bipyramid.
